关于修改pwm占空比后亮度无变化的问题

JaxW · 发表于 2019-8-18 10:10:44

萌新求助：
按下三个key1，key0，wk三个键LED0灯一直都是常亮的，亮度没有变化。
其中按下wk键时LED0灯亮度不变，LED1熄灭。说明关于按键，led部分代码是没有问题的，问题应该出在pwm输出的代码上。

请问我的代码的问题在哪里呢？

JaxW · 发表于 2019-8-18 10:47:34

#include"delay.h"
#include"led.h"
#include"key.h"
#include"pwm.h"
#include"sys.h"
int main (void)
{ u8 t;
int led0pwmval=0;
KEY_Init();
   LED_Init();
   delay_init();
LED1=0;
TIM1_PWM_Init(899,0);
   TIM_SetCompare1(TIM1,led0pwmval);
while(1)
{
t=KEY_Scan(0);
switch(t)
{
case KEY0_PRES:
{
   led0pwmval=led0pwmval-60;
   if(led0pwmval<0)led0pwmval=0;

   TIM_SetCompare1(TIM1,led0pwmval);
      }
   break;
case KEY1_PRES:
   {
     led0pwmval=led0pwmval+60;
   if(led0pwmval>360)led0pwmval=360;
   TIM_SetCompare1(TIM1,led0pwmval);
   }
break;
case WKUP_PRES:
TIM_SetCompare1(TIM1,0);
LED1=1;
break;
      default:
delay_ms(10);
}
}
}

#include"pwm.h"

void TIM1_PWM_Init(u16 arr, u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM_CH1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

TIM_TimeBaseStructure.TIM_Period = arr;
TIM_TimeBaseStructure.TIM_Prescaler =psc;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);

TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);

TIM_ARRPreloadConfig(TIM1, ENABLE);

TIM_Cmd(TIM1, ENABLE);
}